This project aligns well with the strategic goals of NIEHS by: 1) Including investigation of how combined environmental exposures impact disease pathogenesis; 2) Improving understanding of a shared biological pathway, in this case oxidative stress, underlying the impact of these exposures; and 3) Investigating how exposures during pregnancya critical window of susceptibilityrelate to the early life development of the child. This project was initiated this year, and thus does not have any publications to date. However, since beginning my position at NIEHS in January, I have made several substantial steps toward data collection. First, with input from investigators in the Free Radical Metabolism Group (Immunity, Inflammation, and Disease Branch), I have established the laboratory that will be utilized for oxidative stress analyses in urine samples and have a sole source justification pending. Second, I optimized a medical record abstraction form with collaborator Dr. Thomas McElrath to obtain additional information from TIDES participants on specific delivery outcomes. Third, I have received IRB approval for a modification to abstract this data from the Icahn School of Medicine at Mount Sinai. I am now working with the TIDES study team at the four individual study sites to obtain approval for the modifications there as well. Lastly, I have obtained an exemption from NIEHS so that I may utilize the data collected from the study. During the next year I anticipate receiving data on urinary oxidative stress biomarkers, medical record data, and urinary phthalate metabolites from the third trimester of pregnancy, and will begin analyzing data and publishing the results from this study.